cDNA cloning and expression of a novel serine protease in the mouse brain

A cDNA for a novel serine protease, termed brain type granzyme K (B-GRK) was cloned from the mouse brain. The cDNA codes a protein similar to granzyme K (GRK) but completely different at the N-terminus. Genomic Southern and PCR analysis of the gene suggests B-GRK is the alternative transcription form of GRK. B-GRK and GRK have a different organ-specific expression pattern: B-GRK is expressed in the brain, while GRK is expressed in the spleen. The recombinant fusion protein was detected in the neuro2a cells transfected with a plasmid containing B-GRK sequence. The mRNA for B-GRK/GRK was detected in cerebral cortex, hippocampus and diencephalon of the mouse brain. In situ hybridization for B-GRK/GRK revealed that several regions in the forebrain and hypothalamus express the mRNA. Developmental analysis showed that in the prenatal stage, the mRNA was expressed also in pituitary and pineal body in addition to the brain.